Improvement in middllngs-purifiers



G. T. SMITH. Mid-dlings-Puriievrs.

N0.V|54,77Ov. v vPatntedSept.8,1874.

THE GRAPHIC PHOYD-LITMJSI; 4I PARK PLACEJLY the shaker.

AUNITED STATESl PATENT OFFICE,4

GEORGE T. SMITH, OF WASHINGTON, DISTRICT' OF COLUMBIA.

-||v|Trovi-:Merit IN MIDDLINGSTURlI-'II-:Ra

Specification forming part of Letters Patent No. 154,770, dated September 8, 1874-; application filed August 17, 1874.

To all whom it may concern:

Beit known that I, GEORGE T. SMITH, of Washington, in the county of Washington and District of Columbia, have invented certain new and useful Improvements in Middlings-Puriiier; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to such depth as will insure a proper action upon the middlings by the ascending air-currents, and as the ,bulk of material is being constantly reduced as it approaches the tail of the shaker, I have made this invention for the purpose of compensating for such reduction.

The invention embraced in this division consists in making the discharging end of the shaker or bolting-surface of a less width than is the receiving portion of said'boltingsurface, and at the same time correspondingly reducing the area through which the air-current passes.

In the drawing, A A represent the main supporting-frame and case; B, the shaker, divided, by preference, into two or more longitudinal sections by means of ribs b, and hung upon links b2. B is a cam to operate (l is a brush, carried by endless belts. D D are overlapping gather-boards, to collect the middlings which fall through the shaker, and deliver them to the conveyer D".y E is a suctionfan, to draw a current of air upward through the shaker, the airchamber above the shaker being divided, by preference, into sections, by means of partitions E E2.

The devices thus far described may be of any usual or approved construction, and their operation is so well understood that it need not be here described.

b1 are wedgeshaped blocks, secured between the ribs or sides of the sections of the shaker, and in close contact with the boltingcloth, so that the width of such cloth is diminished at the `discharging end. Of course the same result could be attained by drawing towardeach other the sides of the bolt and then distributing the reduction thus effected by changing slightly the position of the lower ends of the ribs b, or by attaching pieces to the sides of the bolt or to the ribs; but I prefer the method shown.

It is apparent that the described construction will maintain a greater depth of middlings on the discharging end of the shaker 4than there would be if the bolting-surface were of uniform width throughout.

A supplemental case composed of sides F, top F', and the overlapping surfaces f f1 f2, is arranged over the upper end of the shaker B. G is a vertical shaft, the lower end of which is mounted in a lever, H, and adjusted vertically by means of a set-screw, h. gis a disk or circular plate, keyed to shaft G. I is a feed-hopper. The neck of the hopper extends through the Atop of the supplemental case to Within a short distance of disk g. K is a suction-fan, employed to exhaust air from this case or chamber.

The middlings are fed in through the hopper I, and are delivered from the disk g, which is driven from any convenient power by a belt and the pulley on shaft G. The aircurrent enters through the space between theV overlapping boards f f1 f2, and passes out through K, carrying with it a portion of the ne refuse. The middlings then pass through the throat a to the shaker B, where they are still further puried by the action of the aircurrent produced by fan E, as will be readily understood.

It is obvious that this narrowing of the bolting-surface might be effected by means of narrow ribs or partitions arranged in converginglines or fan-like form, in place of the Wedge-shaped blocks; but such construction reduction inthe air-passage through the same, substantially as set forth.

In testimony that I claim the.foregoing I have hereunto set my hand this 6th day of August, 1874.

GEORGE T. SMITH.

Witnesses r ELIZA B. SMITH,

H. B. WATERMAN. 

